The C function expects a pointer - a number which refers to a location in the memory space (the HEAP array). You should write the imageData into memory, by getting a buffer from _malloc, then filling ...

And when you pass a pointer into a function it is a copy of the pointer, which is why you don't want to nest functions and keep passing in pointers, the stack will have the pointer multiple times.

I want to Cython wrap a set of C++ functions that return multiple 2D std::vector arrays by passing numpy arrays to it by reference. To illustrate this use case, below is a c++ function that returns ...